Fix metric setting for ifcfg network connections for rhel (canonical#…

…5777)

Most RHEL systems use Network manager to bring up manage network connections.
Network manager does not recognize "METRIC" option for network connections.
It uses IPV4_ROUTE_METRIC and IPV6_ROUTE_METRIC options. Please see
https://people.freedesktop.org/~lkundrak/nm-docs/nm-settings-ifcfg-rh.html

This change ensures that cloud-init generates ifcfg network connection files
with IPV{4/6}_ROUTE_METRIC options that are compatible with RHEL and
network manager.

Fixes canonicalGH-5776

Signed-off-by: Ani Sinha <anisinha@redhat.com>

cloudinit/net/sysconfig.py

@@ -205,7 +205,7 @@ def to_string(self, proto="ipv4"):
                 )
                 metric_key = "METRIC" + index
                 if metric_key in self._conf:
-                    metric_value = str(self._conf["METRIC" + index])
+                    metric_value = str(self._conf[metric_key])
                     buf.write(
                         "%s=%s\n"
                         % ("METRIC" + str(reindex), _quote_value(metric_value))
@@ -548,7 +548,12 @@ def _render_subnets(cls, iface_cfg, subnets, has_default_route, flavor):
             subnet_type = subnet.get("type")
             # metric may apply to both dhcp and static config
             if "metric" in subnet:
-                if flavor != "suse":
+                if flavor == "rhel":
+                    if subnet_is_ipv6(subnet):
+                        iface_cfg["IPV6_ROUTE_METRIC"] = subnet["metric"]
+                    else:
+                        iface_cfg["IPV4_ROUTE_METRIC"] = subnet["metric"]
+                elif flavor != "suse":
                     iface_cfg["METRIC"] = subnet["metric"]
             if subnet_type in ["dhcp", "dhcp4"]:
                 # On SUSE distros 'DHCLIENT_SET_DEFAULT_ROUTE' is a global
@@ -655,7 +660,17 @@ def _render_subnet_routes(cls, iface_cfg, route_cfg, subnets, flavor):
                             iface_cfg["GATEWAY"] = route["gateway"]
                             route_cfg.has_set_default_ipv4 = True
                     if "metric" in route:
-                        iface_cfg["METRIC"] = route["metric"]
+                        if flavor == "rhel":
+                            if subnet_is_ipv6(subnet):
+                                iface_cfg["IPV6_ROUTE_METRIC"] = route[
+                                    "metric"
+                                ]
+                            else:
+                                iface_cfg["IPV4_ROUTE_METRIC"] = route[
+                                    "metric"
+                                ]
+                        else:
+                            iface_cfg["METRIC"] = route["metric"]
 
                 else:
                     # add default routes only to ifcfg files, not

tests/unittests/net/network_configs.py

@@ -204,7 +204,7 @@
                 HWADDR=c0:d6:9f:2c:e8:80
                 IPADDR=192.168.21.3
                 NETMASK=255.255.255.0
-                METRIC=10000
+                IPV4_ROUTE_METRIC=10000
                 ONBOOT=yes
                 TYPE=Ethernet
                 USERCTL=no"""
@@ -376,7 +376,7 @@
                 HWADDR=c0:d6:9f:2c:e8:80
                 IPADDR=192.168.21.3
                 NETMASK=255.255.255.0
-                METRIC=10000
+                IPV4_ROUTE_METRIC=10000
                 ONBOOT=yes
                 TYPE=Ethernet
                 USERCTL=no"""

tests/unittests/test_net.py

@@ -2379,23 +2379,26 @@ def test_from_v2_route_metric(self):
                 }
             },
         }
-        expected = {
-            "ifcfg-eno1": textwrap.dedent(
-                """\
-                BOOTPROTO=dhcp
-                DEVICE=eno1
-                HWADDR=07-1c-c6-75-a4-be
-                METRIC=100
-                ONBOOT=yes
-                TYPE=Ethernet
-                USERCTL=no
-                """
-            ),
-        }
         for dhcp_ver in ("dhcp4", "dhcp6"):
+            expected = {
+                "ifcfg-eno1": textwrap.dedent(
+                    """\
+                    BOOTPROTO=dhcp
+                    DEVICE=eno1
+                    HWADDR=07-1c-c6-75-a4-be
+                    ONBOOT=yes
+                    TYPE=Ethernet
+                    USERCTL=no
+                    """
+                ),
+            }
             v2data = copy.deepcopy(v2base)
             if dhcp_ver == "dhcp6":
-                expected["ifcfg-eno1"] += "IPV6INIT=yes\nDHCPV6C=yes\n"
+                expected[
+                    "ifcfg-eno1"
+                ] += "IPV6INIT=yes\nDHCPV6C=yes\nIPV6_ROUTE_METRIC=100\n"
+            else:
+                expected["ifcfg-eno1"] += "IPV4_ROUTE_METRIC=100\n"
             v2data["ethernets"]["eno1"].update(
                 {dhcp_ver: True, "{0}-overrides".format(dhcp_ver): overrides}
             )